Central nervous system pericytes have critical and complex inductive, structural, and regulatory roles interacting with other
cell types of the neurovascular unit, especially endothelial cells and astrocytes. Pericyte-endothelial interactions are particularly prominent
for blood-brain barrier (BBB) maintenance, with profound effects on basement membrane and endothelial tight junction structure
and function. Under experimental conditions of hypoxia-ischemia mimicking stroke, pericytes migrate from their usual microvascular location
and influence, directly or indirectly, BBB permeability. The contractile properties of pericytes provide the capacity to regulate capillary
blood flow, but this may have detrimental effects on ischemic injury. Stem cell characteristics of pericytes imply an important regenerative
role following stroke. Pericytes thus appear to orchestrate multiple critical functions in stroke, involving blood flow, permeability,
and repair of the neurovascular unit.